Surprise Finding About Human HearingIt turns out, many cells send information to the brain, not just a few
Hearing loss may not be as certain as we think:
For the past 100 years, we have believed that each sensory cell has its own “optimal frequency” (a measure of the number of sound waves per second). The hair cell responds most strongly to this frequency. This idea means that a sensory cell with an optimal frequency of 1000 Hz would respond much less strongly to sounds with a frequency slightly lower or higher. It has also been assumed that all parts of the cochlea work in the same way. Now, however, a research team has discovered that this is not the case for sensory cells that process sound with frequencies under 1000 Hz, considered to be low-frequency sound. The vowel sounds in human speech lie in this area.
“Our study shows that many cells in the inner ear react simultaneously to low-frequency sound. We believe that this makes it easier to experience low-frequency sounds than would otherwise be the case, since the brain receives information from many sensory cells at the same time,” says Anders Fridberger, professor in the Department of Biomedical and Clinical Sciences at Linköping University. The scientists believe that this construction of our hearing system makes it more robust. If some sensory cells are damaged, many others remain that can send nerve impulses to the brain.Linköping University, “New research throws doubt on old ideas of how hearing works” at Medical XPress (September 23, 2022) The paper is open access.